-17.3% is the change from 821 to 679
Calculation steps:
[( 679 - 821 ) ÷ 821] x 100 = -17.3%
Formula
Percentage change = [(679 - 821) / 821] x 100
Subtract the new number by the original number
679 - 821 = -142
-142 ÷ 821 = -0.17295980511571254
-0.17295980511571254 x 100 = -17.3%